Glossary: phase IV trial

Having to do with the examination and treatment of patients.

A type of clinical trial that studies the side effects of a treatment after it has been approved and is being marketed. These trials include thousands of people and look for side effects that were not seen in earlier trials. Also called phase IV trial.

In medicine, the ongoing collection of information about a disease, such as cancer, in a certain group of people. The information collected may include where the disease occurs in a population and whether it affects people of a certain gender, age, or ethnic group.